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Existence of a plant tyrosylprotein sulfotransferase: novel plant enzyme catalyzing tyrosine O ‐sulfation of preprophytosulfokine variants in vitro
Author(s) -
Hanai Hidetoshi,
Nakayama Daisuke,
Yang Heping,
Matsubayashi Yoshikatsu,
Hirota Yuki,
Sakagami Youji
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01299-0
Subject(s) - sulfation , biochemistry , tyrosine , enzyme , amino acid , chemistry , in vitro , sulfotransferase
An in vitro assay system to detect tyrosylprotein sulfotransferase (TPST) activity of higher plant cells was established, using synthetic oligopeptides based on the deduced amino acid sequence of a phytosulfokine‐α (PSK‐α) precursor. TPST activity was found in microsomal membrane fractions of rice, asparagus and carrot cells and it was confirmed that acidic amino acid residues adjacent to the tyrosine residues of acceptor peptides were essential to the sulfation reaction. The asparagus TPST exhibited a broad pH optimum of 7.0–8.5, required manganese ions for maximal activity and appeared to be a membrane‐bound protein localized in the Golgi apparatus. These enzymes should be defined as a new class of plant sulfotransferases that catalyze tyrosine O ‐sulfation of a PSK‐α precursor and other unknown proteins.